Toronto Public Health: Mosquitoes Test Positive For West Nile Virus In Toronto



Toronto Public Health (TPH) received a laboratory report today indicating that mosquitoes in Toronto have tested positive for West Nile Virus (WNV). This is the first WNV positive result for Toronto this year.

“This finding of mosquitoes carrying West Nile Virus is earlier in the season than previous years. It is a good reminder for the public to protect themselves from mosquito bites, and to reduce mosquito breeding grounds by draining standing water around your home,”said Dr. Howard Shapiro, Associate Medical Officer of Health for Toronto Public Health. TPH has 43 mosquito traps throughout the city and sends mosquitoes for laboratory testing every week.

Larvicides are placed in roadside catch basins throughout the city to reduce the mosquito population.

The West Nile Virus was first discovered in Toronto in 2001, and in 2002 there were 163 known cases and 11 deaths. There have been no deaths in Toronto from WNV since 2005. In 2011, TPH reported 76 positive mosquito batches and 28 human cases of illness reported due to the virus. The Ministry of Health and Long-Term Care reported 71 human cases in Ontario in 2011.

Although the risk of becoming infected is low, protection against mosquito bites can lower this risk further. The following measures are recommended:

● Use mosquito repellent approved by Health Canada.

● Wear light-coloured clothing and cover up when in areas where mosquitoes are present.

● Take extra precautions, especially in early morning and early evening, when mosquitoes are most active.

● Remove standing water around your home and property.


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